multiple BOOT tools/OS from one USB?

[ingear]

I know we can make a boot USB ...

say Acronis True Image or UBCD4WIN or UBCD and DBAN

but if I have one USB stick

how can I put multiple boots? (maybe make 2 .. 3 .. 4 .. USBs and then copy paste the files onto one USB?)

and select which to boot?

thank you ...

PS hmm will this work - partition the USB
and
install a boot manager in one of the partitions
and etc ... here http://bnsmb.de/Rescue/Rescue_USB_Stick.html#mozTocId667481